达到最大宽度时如何在x轴上进行行滚动（溢出）

时间：2019-02-05 07:18:30

标签： html css bootstrap-4

我希望如果超过最大宽度，它应该能够滚动。我尝试将宽度设置为100％并按其他stackoverflow文章中的说明将溢出x：auto和white-space：nowrap设置为有效，但是它对bootstrap col无效。我还尝试使用flex和flex溢出，还尝试通过添加容器流体来进行尝试，但是尽管滚动条显示但无法滚动，但仍然具有相同的结果

对于我当前的输出，如果col大于18，它将断开并转到我不想要的新行，我希望它能够滚动而不是将行插入新行

import Foundation
import UIKit

class InvertedFlowLayout: UICollectionViewFlowLayout {

    override func prepare() {
        super.prepare()
    }

    override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
        guard super.layoutAttributesForElements(in: rect) != nil else { return nil }
        var attributesArrayNew = [UICollectionViewLayoutAttributes]()

        if let collectionView = self.collectionView {
            for section in 0 ..< collectionView.numberOfSections {
                for item in 0 ..< collectionView.numberOfItems(inSection: section) {
                    let indexPathCurrent = IndexPath(item: item, section: section)
                    if let attributeCell = layoutAttributesForItem(at: indexPathCurrent) {
                        if attributeCell.frame.intersects(rect) {
                            attributesArrayNew.append(attributeCell)
                        }
                    }
                }
            }

            for section in 0 ..< collectionView.numberOfSections {
                let indexPathCurrent = IndexPath(item: 0, section: section)
                if let attributeKind = layoutAttributesForSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader, at: indexPathCurrent) {
                    attributesArrayNew.append(attributeKind)
                }
            }
        }

        return attributesArrayNew
    }

    override func layoutAttributesForSupplementaryView(ofKind elementKind: String, at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        let attributeKind = UICollectionViewLayoutAttributes(forSupplementaryViewOfKind: elementKind, with: indexPath)

        if let collectionView = self.collectionView {
            var fullHeight: CGFloat = 0.0

            for section in 0 ..< indexPath.section + 1 {
                for item in 0 ..< collectionView.numberOfItems(inSection: section) {
                    let indexPathCurrent = IndexPath(item: item, section: section)
                    fullHeight += cellHeight(indexPathCurrent) + minimumLineSpacing
                }
            }

            attributeKind.frame = CGRect(x: 0, y: collectionViewContentSize.height - fullHeight - CGFloat(indexPath.section + 1) * headerHeight(indexPath.section) - sectionInset.bottom + minimumLineSpacing/2, width: collectionViewContentSize.width, height: headerHeight(indexPath.section))
        }

        return attributeKind
    }

    override func layoutAttributesForItem(at indexPath: IndexPath) -> UICollectionViewLayoutAttributes? {
        let attributeCell = UICollectionViewLayoutAttributes(forCellWith: indexPath)

        if let collectionView = self.collectionView {
            var fullHeight: CGFloat = 0.0

            for section in 0 ..< indexPath.section + 1 {
                for item in 0 ..< collectionView.numberOfItems(inSection: section) {
                    let indexPathCurrent = IndexPath(item: item, section: section)
                    fullHeight += cellHeight(indexPathCurrent) + minimumLineSpacing

                    if section == indexPath.section && item == indexPath.item {
                        break
                    }
                }
            }

            attributeCell.frame = CGRect(x: 0, y: collectionViewContentSize.height - fullHeight + minimumLineSpacing - CGFloat(indexPath.section) * headerHeight(indexPath.section) - sectionInset.bottom, width: collectionViewContentSize.width, height: cellHeight(indexPath) )
        }

        return attributeCell
    }

    override var collectionViewContentSize: CGSize {
        get {
            var height: CGFloat = 0.0
            var bounds = CGRect.zero

            if let collectionView = self.collectionView {
                for section in 0 ..< collectionView.numberOfSections {
                    for item in 0 ..< collectionView.numberOfItems(inSection: section) {
                        let indexPathCurrent = IndexPath(item: item, section: section)
                        height += cellHeight(indexPathCurrent) + minimumLineSpacing
                    }
                }

                height += sectionInset.bottom + CGFloat(collectionView.numberOfSections) * headerHeight(0)
                bounds = collectionView.bounds
            }

            return CGSize(width: bounds.width, height: max(height, bounds.height))
        }
    }

    override func shouldInvalidateLayout(forBoundsChange newBounds: CGRect) -> Bool {
        if let oldBounds = self.collectionView?.bounds,
            oldBounds.width != newBounds.width || oldBounds.height != newBounds.height {
            return true
        }

        return false
    }

    func cellHeight(_ indexPath: IndexPath) -> CGFloat {
        if let collectionView = self.collectionView, let delegateFlowLayout = collectionView.delegate as? UICollectionViewDelegateFlowLayout {
            let size = delegateFlowLayout.collectionView!(collectionView, layout: self, sizeForItemAt: indexPath)
            return size.height
        }

        return 0
    }

    func headerHeight(_ section: Int) -> CGFloat {
        if let collectionView = self.collectionView, let delegateFlowLayout = collectionView.delegate as? UICollectionViewDelegateFlowLayout {
            let size = delegateFlowLayout.collectionView!(collectionView, layout: self, referenceSizeForHeaderInSection: section)
            return size.height
        }

        return 0
    }
}

2 个答案:

答案 0 :(得分：2)

这是您想要实现的目标的有效示例。

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <link href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/css/bootstrap.min.css" rel="stylesheet">
    <style type="text/css">
        .my-div {
            width: 300px;
            background-color: red;
            color: white;
            border: 2px solid white;
            display: inline-block;
        }
    </style>
  </head>
  <body>
    <div class="container">
        <div class="row">
            <div class="col-md-12" style="overflow-x: scroll; white-space: nowrap;">
                <div class="my-div">
                    my div   
                </div>
                <div class="my-div">
                    my div
                </div>
                <div class="my-div">
                    my div
                </div>
                <div class="my-div">
                   my div
                </div>
                <div class="my-div">
                    my div
                </div>
            </div>
        </div>
    </div>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
    <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.1/js/bootstrap.min.js"></script>
  </body>
</html>

这里是场景： enter image description here

答案 1 :(得分：0)

/* The heart of the matter */
.testimonial-group > .row {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
}
.testimonial-group > .row > .col-xs-4 {
  flex: 0 0 auto;
}

/* Decorations */
.col-xs-4 { color: #fff; font-size: 48px; padding-bottom: 20px; padding-top: 18px; }
.col-xs-4:nth-child(3n+1) { background: #c69; }
.col-xs-4:nth-child(3n+2) { background: #9c6; }
.col-xs-4:nth-child(3n+3) { background: #69c; }
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

<div class="container testimonial-group">
  <div class="row text-center">
    <div class="col-xs-4">1</div><!--
 --><div class="col-xs-4">2</div><!--
 --><div class="col-xs-4">3</div><!--
 --><div class="col-xs-4">4</div><!--
 --><div class="col-xs-4">5</div><!--
 --><div class="col-xs-4">6</div><!--
 --><div class="col-xs-4">7</div><!--
 --><div class="col-xs-4">8</div><!--
 --><div class="col-xs-4">9</div>
  </div>
</div>

/* The heart of the matter */
.testimonial-group > .row {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
}
.testimonial-group > .row > .col-xs-4 {
  flex: 0 0 auto;
}

/* Decorations */
.col-xs-4 { color: #fff; font-size: 48px; padding-bottom: 20px; padding-top: 18px; }
.col-xs-4:nth-child(3n+1) { background: #c69; }
.col-xs-4:nth-child(3n+2) { background: #9c6; }
.col-xs-4:nth-child(3n+3) { background: #69c; }
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">

<div class="container testimonial-group">
  <div class="row text-center">
    <div class="col-xs-4">1</div><!--
 --><div class="col-xs-4">2</div><!--
 --><div class="col-xs-4">3</div><!--
 --><div class="col-xs-4">4</div><!--
 --><div class="col-xs-4">5</div><!--
 --><div class="col-xs-4">6</div><!--
 --><div class="col-xs-4">7</div><!--
 --><div class="col-xs-4">8</div><!--
 --><div class="col-xs-4">9</div>
  </div>
</div>

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